1. Field of Invention
Fabricated cushioning material in which a filler of discrete particles are encapsulated in loose condition in a confining envelope.
2. Description of Prior Art
Pads, mattresses and cushions stuffed or filled with loosely packed discrete particles so that they conform to the contour of the engaged portion of a body or article supported thereby are known in the art. Generally these cushions or mattresses are, in turn, supported on a supporting structure such as springs or a chair seat which may be rigid or elastic. As a pad, the material may be used as a splint and wound about or otherwise held against an injured part of the body. The case is of gauzelike woven fabric and only 80 to 90% filled with particles. Such a structure is disclosed in U.S. Pat. No. 3,459,179, Aug. 5, 1969 entitled "Supporting Pad with Massaging Means." A great amount of handwork is required to fabricate such cushioning material, with the result that they are very expensive.
Sometimes resilient particles, such as soft rubber or sponge rubber, are used and dispersed through a mass of fibre stuffing within the mattress or cushion, one of the earlier examples of this combination being U.S. Pat. No. 74,340 issued in 1868, and showing cushions stuffed with fibre and hollow elastic blocks or globules.
The present invention is directed primarily to a unitary cushioning structure, self-conformable to the contour of the surface of an object pressed thereagainst, in which a quantity of discrete particles is encapsulated in a flexible, tear resistant, cover or casing so as to completely fill the casing. If a relatively rigid supporting structure is to be used in connection with the cushioning structure, it may be integral therewith. If a flexible or resilient supporting structure is to be used in connection with the cushioning structure, as for example in the case of shoe soles, the integral base may be flexible or resilient. More particularly, the invention is directed to a method of molding the unitary cushioning structure by the application of controlled heat and pressure to a charge comprising globular particles or beads of raw thermoplastic or thermosetting material, each of which is hereinafter referred to as thermo-meltable material.
The thermo-meltable particles used are relatively inexpensive and the method of manufacture is simple and requires little or no hand labor, so that the manufacturing cost is low, making the structure practical commercially for many fields of use in which heretofore it was unduly expensive. The unitary molded structure is free from extraneous connecting or fastening means, and lends itself to use as a base material for forming many specific articles by simple combined cutting and heating steps applied to localized areas of the structure.
Various other objects and advantages will become apparent from the following description in which reference is made to the drawing.